Many conventional lighting fixtures (luminaires) include high efficiency fixtures and automated controls that make adjustments based on occupancy, e.g., sensors allow for operation whenever someone is within a scanned area, or daylight sensing, e.g., sensors allow for operation based on the amount of sunlight within a scanned area. These passive infrared (PIR) motion detectors are widely used on both indoor and outdoor lighting of commercial, industrial, and residential spaces to provide the proper lighting given factors such as time of day and position of lighting, among others.
When an infrared emitting object, such as a person, enters the viewing zone of the sensor, the lamps connected to the sensor are automatically activated to illuminate the desired area at which the lamps are aimed. One problem with such controls is that the viewing zone of the sensor is limited causing the lamps not to automatically activate if the infrared emitting object approaches the light fixture from an angle outside the viewing zone.
Previous attempts to broaden the viewing zone of automatic lighting fixtures have been attempted. One solution includes use of wide-angle motion detectors designed to extend the viewing zone of the sensor to an angle greater than 180 degrees by using a plurality of inclined infrared mirror faces, designed to direct sufficient intensity of radiation to the sensor from outlying angles. However, non-precision measuring instruments such as mirrors retain dirt or fog over time, thus reducing the operation of the sensor. Additionally, with only one measuring device, the system is susceptible if the sensor fails.
Another solution includes a motion detector assembly with a primary motion sensor and a secondary motion sensor. However, both the primary and secondary motion sensors use infrared sensors rather than more precise detection systems. Additionally, slight adjustments to either of the sensors could lead to an unintended viewing zone.
Additionally, mounting PIR sensors onto existing luminaires can be complicated and cumbersome. Furthermore, positioning installed PIR sensors can be time consuming to ensure proper direction an accuracy.